Adidas Adizero SL2 review

We're impressed with the Adizero SL2, and we believe it's a great pick for:

• Anyone seeking a lightweight running shoe versatile enough for any kind of run, including track workouts.
• Fans of the original SL2 who crave a more responsive midsole without sacrificing the beloved fit and affordability.
• Neutral runners who prioritize speed and agility over stability in their daily running shoe.

We do not recommend the Adidas Adizero SL2 for those in search of a maximalist daily trainer with ample cushioning, particularly heavier runners. Our lab tests indicate that the ASICS Novablast 4 offers superior cushioning and is a better choice for those concerned with comfort that are seeking a lightweight running shoe.

Additionally, the SL2's outsole was a bit disappointing—it still lacks Continental rubber, compromising both durability and grip. For those concerned, we suggest the Adidas Adizero Adios 8 for durability and the PUMA Velocity Nitro 3 for exceptional traction.

Adidas has maintained the 34.9 mm heel stack from the first-gen SL.

In an era dominated by maximalist shoes, maintaining this level of cushion offers a welcome alternative for those who prefer a closer ground feel and a less bulky option.

In our lab, adhering to World Athletics guidelines, we measured the forefoot at 26.7 mm—around the average and a solid design for a daily driver.

Our measurements revealed a real 8.2-mm drop—remarkably close to the official 9-mm specification. This offset renders the shoe exceptionally versatile, suitable for any footstrike, though we discovered it truly excels for midfoot strikers.

And hey, take a look at that long slab of white foam—that's the big update for the SL2! It's now equipped with full-length Lightstrike Pro. We'll explore this further in our "Midsole" section in just a bit.

While previous changes to the SL might not have fully warranted an upgrade to the SL2—especially with older models typically discounted in every online store—this one certainly does.

Previously, the SL only had a small puck of Lightstrike Pro in the forefoot and didn't felt really responsive. Now, it boasts a substantial, full-length slab of this premium superfoam, making it an outstanding value at $130, with no close competitors currently on the market.

The ride has the classic Lightstrike Pro feel we've noted in many other models like the Adios 8. It's not plush, measuring at 20.1 HA, yet it offers an elastic quality that provides world-class energy return, outperforming every EVA foam out there.

While the SL2 incorporates significantly more Lightstrike Pro than its predecessor, it also maintains a substantial amount of EVA-based Lightstrike 2.0 as a carrier foam. This setup encloses the more advanced foam, enhancing durability. It's also important to note that most of the Lightstrike 2.0 material is present in the heel, with only a smaller portion in the midfoot and forefoot.

This secondary foam is slightly softer than the primary, measuring at 19.5 HA, offering a well-balanced feel that isn't firm. On the other hand, while this midsole configuration boosts durability and affordability, it doesn't deliver the high energy return characteristic of Lightstrike Pro.

We subjected the SL2 to a chilling test—20 minutes in the freezer—to gauge how the Lightstrike Pro foam would respond under low temperatures. The outcome was quite remarkable; the foam only became 5% firmer, underscoring its robust performance across various climates!

The insole is notably thinner than typical, measuring just 3.4 mm. We really like this slimmer design for the SL2 as it maintains a low-profile build.

The Adizero SL2 is a nod to classic racing flats, perfect for runners who prefer a traditional feel over a highly rockered design.

This type of mild-and-late rocker excels at building foot strength because it lacks plates or steep angles—and we're big fans because it distinctly diverges from current market trends.

For those already fond of the SL and curious about its successor, it's no shock that the SL2's toebox is again impressively roomy.

Our initial measurement at the upper's widest part registered 101.8 mm, ranking it among the most spacious daily trainers we've tested in the lab.

The big toe area maintained a comfortable average width of 77.6 mm. This is suitable for most feet, yet it presents a more tapered design compared to other shoes.

In terms of volume, this is the classic Adizero upper that offers a snug, low fit. While it's not a major concern, those who often experience toe pressure might want to avoid long runs in the SL2.

The Adidas Adizero SL2 is a 100% neutral running shoe, as it lacks the modern supportive features like sole flares and reinforced sidewalls, making it a bad pick for runners with even low stability needs. 

We think that Adidas fans concerned with stability should pick the Supernova Rise, which offers a broader platform and a more stable ride throughout.

The original SL caught us off guard with its high torsional stiffness—a feature we didn't appreciate much for a lightweight daily trainer. Fortunately, Adidas has made a significant adjustment, and we now rate it a moderate 3 out of 5, which aligns much better with its design.

The heel counter in the SL2 draws its design from the Adizero line, scoring a low 2 out of 5 in our manual flexibility assessment.

Yet, it excels in execution—offering abundant padding and robust heel lockdown. This combination makes it ideal for runners with sensitive Achilles tendons or those dealing with Haglund's deformity, as it provides a good amount of flexibility without exerting pressure on the heel area while running.

The SL2 sports a classic, streamlined silhouette reminiscent of the Adizero Takumi Sen 10, a shoe that appears to have heavily influenced its design.

It maintains a narrow profile without an expanded midfoot. In addition, we did not find a wide forefoot; in fact, it measured a rather slim 113.0 mm, narrower than most other shoes in its category.

Instead, we recommend the New Balance FuelCell Rebel v4 for a stable and lightweight running experience.

Like many Adidas running shoes, the exaggerated lateral heel bevel in the SL2 provides some lateral resistance, and it can assist runners with very mild pronation issues, though we firmly believe that this shoe is primarily designed for neutral runners.

In the "Rocker" section, we noted that the SL2 offers a classic ride reminiscent of an old-school racing flat, challenging the foot muscles to work harder and strengthen. However, achieving this also required one critical factor—reduced longitudinal stiffness.

Fortunately, the SL2 lacks a plate and checks this box—it clocked just 22.8N in our 90-degree bend test.

With the addition of Lightstrike Pro superfoam, we discovered that stiffness only increased by 18.9% in cold temperatures.

Weighing in at 8.6 oz or 245g, the Adizero SL2 upholds its reputation as a lightweight daily trainer. However, while Adidas promotes the SL for Super Light, our findings suggest it doesn't quite hit the "Super" mark.

We also found that it retains the same effortless feel as its predecessor, with this latest version managing to shave off a minor 0.2 ounces, enhancing its appeal. Despite that, it remains still far from the lightest trainers available, and we recommend considering the Brooks Hyperion if shoe weight is a critical factor for you.

Being part of the Adizero family, we expected Adidas to prioritize performance and lightness in the SL2—and that's exactly what we discovered.

Upon testing the upper with our smoke machine, we observed impressive airflow, placing the SL2 among the most breathable shoes we've tested, and it earned a well-deserved 5/5.

Instead of typical ventilation holes for heat and moisture evacuation, Adidas utilized a monomesh upper densely packed with ultra-small gaps across the toebox and midfoot.

Examining the single-layer mesh under the microscope provided stunning visuals—we're amazed at the precision achieved in crafting running shoe uppers today.

While we don't anticipate high durability scores due to its thin and airy construction, our current impressions are positive. Ventilation is excellent, and we noted considerable padding in the tongue and heel, impressive for such a lightweight shoe.

Unfortunately, our worst fears were confirmed during our Dremel test on the Adizero SL2.

The upper offered no resistance and immediately succumbed as soon as the sandpaper tip touched it, resulting in a full hole. This obviously earned it our lowest possible durability rating—a dismal 1/5.

However, the situation improved dramatically in the heel area, where we observed a complete turnaround.

Although the toebox lacked durability, the heel lining withstood this test impressively, earning a perfect score of 5 out of 5 from our team.

Following mixed outcomes in our initial tests, we now turn our attention to the outsole—a crucial component for any budget-friendly shoe like this one.

Our assessment of the rubber's hardness yielded an average 79.8 HC. This is softer compared to the original Adizero SL—a change that makes sense to us, as our test runs indicated a slight improvement in traction. But we would love so much to have Continental in this shoe...

Finally, an interesting aspect of the outsole design is that it draws inspiration from the ultra-expensive Adidas Adizero Prime X 2 Strung, featuring three cutouts in the forefoot, even though it lacks a carbon plate or Energy Rods.

Adidas typically excels in outsole durability, yet the Adizero SL2 falls short. While the first version withstood our Dremel test well—suffering only a 0.7 mm dent—we discovered that this updated version got 1.1 mm of damage.

Although not disastrous, this decrease in durability is a noticeable step back and could raise concerns about longevity for some runners.

Adidas wisely decided to increase the outsole thickness to offset the diminished durability, a move we validated with our vernier calipers that measured a robust 3.6 mm.

In our view, this shoe stands out as an exceptionally well-priced option. In fact, we haven't encountered any running shoe besides the Adizero SL2 that combines premium foam with a lightweight design... at a lower price than the Nike Pegasus 41!

We discovered that Adidas omitted all reflective elements from the SL2—no surprise to us at all!

The original SL boasted an ideal tongue thickness for a lightweight shoe at 4.1 mm—adequate to prevent lace bite while maintaining comfort. However, Adidas has inexplicably tripled this to 12.7 mm in the SL2.

We believe this was an unnecessary change. The previous model had no issues with instep comfort or lace bite, so this adjustment only makes the fit more cramped and wastes an opportunity to reduce weight.

The tongue isn't attached to the sides, yet thanks to ample padding in this area and a low-volume toebox, we didn't observe any unwanted movement. Plus, considering its competitive pricing, we understand why Adidas might skip this feature.

Since the launch of the Adidas Adizero Adios Pro 3 in 2022, Adidas has consistently incorporated heel pull tabs into their Adizero line designs. And we discovered that the SL2, even as the entry-level model in this series, follows this trend.

While you can remove the insole of the SL2, we think that it's generally not advisable. The original insole is ideally suited for this model—thin and perforated to enhance breathability.

Replacing it with a thicker option might lead to a tight toebox, compromising comfort.